Electric heating oven



' Sept; 16, 1969 A.'C. ROBINSON ELECTRIC HEKI'ING OVEN l0 Sheets-Sheet 2 Filed Sept. 21, 1965 I 4 mvswrox C, EOE/NSOIV,

BY QMZ W p 6, 1969 A. c. ROBINSON ELECTRIC HEATING OVEN 10 Sheets-Sheet 4 Filed Sept. 21, 1965 V41. VE W/IEEL.

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p 1959 A. c. ROBINSON 3,467,815

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A. C. ROBINSON ELECTRIC HEATING OVEN Sept. 16, 1969 10 Sheets-Sheet 9 Filed Sept. 21, 1965 FIG. 20.

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C. E081 A/so/v AUBREY Sept. 16, 1969 A. c. ROBINSON ELECTRIC HEATING OVEN 1O Sheets-Sheet 10 Filed Sept. 21, 1965 INVENTOR.

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United States Patent 3,467,815 ELECTRIC HEATING OVEN Aubrey Clyde Robinson, Rte. 3, Avery Drive, La Grange, Ga. 30240 Filed Sept. 21, 1965, Ser. No. 488,886 Int. Cl. F2711 11/02 U.S. Cl. 219-400 13 Claims ABSTRACT OF THE DISCLOSURE An electric heating oven system for heat treating food products and other products by passing of heated currents of air over them and avoiding direct radiation of heat onto the products. A system of sensing devices and controls maintains the temperature of the air currents within close limits. The system is particularly suitable for large roasts of meat. The volume of circulating air is controlled as well as its temperature. Provision is made for continuously turning roasts of meat.

The present invention relates to an electric heating oven system for the heat treatment of various objects, but more particularly, for the cooking of meat and other food products by passing currents of air thereover.

It is an object of my invention to provide an electric heating oven system which can be precisely controlled to apply uniformly required heat volume at desired temperature levels simultaneously to a number of objects to be cooked, such as, large roasts or other objects.

Another object of my invention is to provide an electric oven in which heat is applied to the material to be heated or cooked in heated streams of air or vapor and not by direct radiation from heating elements.

Still another object of my invention is to provide shielding jackets to enclose the heating elements through which a current of air circulates while preventing direct radiation of heat from the heating elements on to the objects to be heat treated.

A further object of my invention is to provide elimination of all storage heat usually functioning in ovens as heat sink and used to reduce temperature by relating mass of metal volume to volume of heat generated, to receive heat when the oven is overheating, and to rerelease heat to the oven when the oven -is underheating, thus, providing a thermal delay action in the heat environment in which temperature sensing devices are placed.

A further object of my invention is to provide by the absence of any thermal delay characteristics inside the oven, itself, a sensing environment which is instantly responsive to generation of out-going heat, and, conversely, to which variable regulation for heat generation is also instantly responsive to sensing devices.

A further object of my invention is to provide a method for temperature sensing response controlled switching on and/or oif heating coils of varying heat generating capacities, and as located together in each heat generating assembly, to operate singly or in combination with each other so that heat volume may be varied up or down in a continuous heat generating process, without the use of expensive variable transformers or saturables and the elaborate control mechanisms required therefor.

A further object of my invention is to provide a method for a compound temperature sensing response operation of varying both the volume of circulating air and the volume of heat generation in relation to each other to regulate the volume of heat required to maintain a stabilized cooking or heating process at desired temperature levels, as preset for the high and low temperature points, namely, the beginning temperature and the ending temperature of the air in its passage around and by the cook- 3,467,815 Patented Sept. 16, 1969 in g objects where heat volume generated will be precisely that which is absorbed by the meat.

A further, and very important object of my invention is to provide a safe method for low heat cooking Where the ending temperature of the air passage over the meat can be reduced to the lowest point possible to still prevent the multiplication of various bacterial cultures involved in meat or food spoilage.

A further object of my invention is to eliminate the necessity for turning meat While in the cooking process for purposes of preventing over-cooking at various portions, or for crusting control, by reversing the flow of air circulation at desired point or points in the cooking process.

Still another very important objective of this invention is to make applicable to textile goods, as well as to meat and other foods, a heat treatment resulting from even generation and dispersal of heat, with the compound sensing system controlling both air flow and heat generation, to protect delicate cotton fibers, as blended with synthetics, from the ravages of both unintentional overheating, and from peak heat intensities fixed higher than necessary to protect against unintentional underheating.

Another objective, in connection with the objective just outlined, is to provide an arrangement of plural separate, and independently operating, units of heat treatment, in series, one unit with another, to accommodate a tempering heat treatment procedure whereby the heat intensity imposed on textile goods can be imposed in stages of intensity levels for each succeeding unit until peak heat intensity for curing is reached, and after the curing exposure, where the heat intensity necessary for curing as applied in the textile goods, can conversely, be withdrawn therefrom in stages with a brief time interval in each unit to permit some seasoning of the cure as respective lower heat intensities are reached successively as down to ambient temperature.

Still another objective of this invention, is that by removing economic hazards formerly met from under-heating of the textiles in conventional ovens, to reduce the need for peak heat intensity levels presently used, so that lower peak heat intensity levels can be used which can result in lowering the proportion of synthetic materials and bonding additives in the blend mix with cotton materials necessary for permanent shape memory in washand-wear goods.

Still another objective of this invention is to widen the scope of materials and products which may undergo heat treatment in this manner, to include products of metals, ceramics, Wood, chemical compounds, lacquers, etc.

My invention will be understood from the following specification and the accompanying drawings in which:

FIG. 1 shows, on the right side, a cross-sectional view of the arrangement of the fixed controls as positioned in the interior of an oven space, and, at the left side a blown-up view of the panel on which the variable controls are mounted, with box configurations of these individual control units, or specialty electrical components, as placed, each one, adjacent to the component it controls, and, also, line configurations for each set of sensing elements, two thermistors in each set with circuit wires therefrom, as control lines to sensing locations so indicated back to control boxes on control panel.

FIG. 1a shows a top plan view of the oven assembly.

FIG. 2 shows the external perspective view of the oven casing of the oven in which fixed controls are located, with the control panel and fan motor attached thereto.

FIG. 3 is a vertical view through the oven casing taken on the line 33 of FIG. 2, showing heating elements mounted in positioned groups.

FIG. 4 shows a pair of heating elements on a mounting base and their connecting wires.

FIG. 5 is a view taken on line 5-5 of FIG. 3 and shows the structure of heating jackets with heating elements mounted inside, and a thermistor temperature sensing element mounted nearby.

FIG. 6 is a vie-w taken on line 6-6 of FIG. 2, showing a plurality of roasts mounted on a plurality of shafts disposed transversely of the oven casing, and a fan to direct currents of air thereon.

FIG. 7 shows a view taken on line 77 of FIG. 2, and shows a cross-sectional view of the oven casing including a plurality of shafts on which roasts are mounted, and a plurality of heating elements mounted in shielding jackets, and air conduits through which currents of air are directed by the fan.

FIG. 8 shows details of a temperature sensing response control switching system which is represented as a box in FIG. 1.

FIG. 9 shows a side view of details of the mounting of one heating element.

FIG. 10 shows details of the program switch, which is represented as a box in FIG. 1.

FIG. 11 shows details of vertical section showing baffie metal adapters to direct air horizontally from one heating jacket to the next, and arranged as shelves on which to place roasts or cuts of meat, in containers containing liquids, or pans of baking materials.

FIG. 12 shows a view taken on line 12-12 of FIG. 11 and shows a plan view of the metal bafile and heating jacket adjacent thereto.

FIG. 13 shows a perspective view of the fan traverse cut-out of the fan plate separating the cooking compartment from air head above the fan, and air channels opening therein.

FIG. 14 shows details of linear resistance variable regulator in series with power feed to fan motor, and represented as a box in FIG. 1.

FIG. 15 shows elements of variable heat generation output of heating elements located in one location in one heating jacket, and electromagnetic power switches therefor, which electromagnetic power switches are represented as a box in FIG. 1.

FIG. 16 shows, at the bottom, the elements of variable heat generation shown in FIG. 15 extended to plural locations in respective heating jackets from one group of circuits, with the power load of each circuit of heaters divided equally by each phase of a three phase circuit, and electromagnetic power switches therefor, which electromagnetic power switches are represented as a box in FIG. 1. And further shows at the top thermistor elements in the control lines positioned in one lower cooking compartment as shown in FIG. 1.

FIG. 17 is a perspective view of heating units assembled together in series.

FIG. 18 is a perspective view on an array of plural assemblies of the units of FIG. 17 arranged longitudinally and transversely in rows.

FIG. 19 is a view in cross-section showing the interior space arrangement providing the air return channels on the edges.

FIG. 20 is a view in cross-section of one cell of FIG. 17.

FIG. 21 is a top view of one of the cells of FIG. 17 showing the section of the conveying means for the objects to be heated, and

FIG. 22 is a top view of one of the cells of FIG. 17 showing the conveyor system.

Referring to the drawings in details, in FIG. 1, 1 is a channel within the inner wall of oven 100 and partition 101 of the oven through which a current of air generated by fan 8 passes downward to an aperture 3 through which the current of air passes upward through jacket enclosure 7 around heating coils 12 and out through an aperture, or, vent 4, and on upward through the oven, as, simultaneously a similar-current of air also generated by fan 8 passes downward through channel 2 within partition 101 and partition 102 to a similar air aperture 3 and upward through a similar jacket 7 around heating coils 12 and out through similar aperture or vent 4 and upward through the oven, intermixing as necessary the current of air emitted upward from channel 1, Intermixed or composite air current 1 from the aforementioned channels and companion outer and inner channel 1 and 2 at the right side of the oven continue upward, and around cuts of meat 11; to another set of heating jackets 12 at an upper horizontal level in the oven, whereupon the composite current of air pushes in through four respective apertures 3 of the four heating jackets 7 and around heating coils 12 in second level jackets and around cuts of meat 11 positioned in the upper level compartment of the oven and finally returns to fan 8, or bounces to fan 8 by plate 103, shown also in FIG. 13, and thus to repeat circulation cycle over and over again. Channels 1 and 2 are equal volume channels, and heating jackets 7 formed by two adjacent insulated wing troughs 6 each with an insulated Wing heel shield 5, are mounted in both lower and upper levels of mounting in such a manner as to form equal distributive volume units for intake and dispersal of air in relation to horizontal void of the oven, and in relation to symmetrically placed cuts of meat 11; fan 8, as it revolves, traverses a circle for the entire horizontal span of the oven void, and together with plate 103, completes an air circulatory system whereby air is dispersed in uniform volume as related to the inner space of the oven and its cooking contents.

Referring now to parts of the drawings which relate to the heating system, in function sequences, plural electric heating coils 12 with schematized variance in wattage capacity 12a, 12b, 12c, 12d, 122 (FIG. 15) are used together in respective locations or jackets, and positioned and mounted as shown in FIGS. 1, 4, 5, 3, 7, 9, 11, 15 and 16, etc., and are energized directly from 220-236 volt power-in A.C. lines shown in detail in FIG. 16. Power switching is controlled by respective electrimagnetic switches 124, FIG. 15, which are actuated by temperature sensing response mechanisms and systems which are referred to separately, as follows:

FIG. 8 shows the mechanisms or electrical components used together as a method for producing motor rotation action as controlled by temperature sensing responses, which are: two identical double pole electromagnetic switches, 18, where one pole of each switch is in reverse contact position from that of the other pole of the same switch, namely, one pole open when switch is de-energized, and closed when switch 18 is energized, and open when switch 18 is de-energized. There are two jumpers 19, one each connecting like poles of the two switches 18 to gether; two identical transistorized Wheatstone bridge type controllers 16, such as Fenwall commercial type or equivalent, and each controller with its individual sensing circuit to a thermistor sensing element, 20, and each controller, 16, with its individual variable resistor, 17, or potentiometer, which is calibrated in temperature setting. Each controller is powered from volt A.C. leads 14+15 and actuates a separate one of the two double pole electromagnetic switches, 18. One lead coming also from tap ofif lead 14 of volt A.C. power circuit has a T connection to both movable contactors of one electromagnetic double pole switch; and the two lugs, or stationary contacts, of like poles of each electromagnetic switch are connected sequentially together by respective jumpers 19; where the second electromagnetic switch 18, not connected directly to power lead 14 has off-feed leads 24-25 to operate as follows; movable contractor of switch 18 which is closed when its switch is de-energized is connected by power lead 25 to reversible motor 23 at a coil position to complete power circuit to motor 23 so that the motor rotates in clockwise direction; movable contactor of the same lower electromagnetic switch 18 closed when its switch 18 is energized, is connected by lead 24 of the same motor 23 to complete the power circuit at a coil position so that the motor rotates in a counter-clockwise direction. With mechanism so arranged as described above,

a method for the operation of a temperature sensing response is evolved as follows: The variable resistors'17 of the two controllers 16 are set close but not quite together, down to within 3 degrees Fahrenheit apart: the sensing elements 20 of both controllers 16 are placed in the same temperature environment; each of the two controllers 16 has a two degree dilferential between make energized, and break de-energized; if and when the temperature is at or below or falls to 1 degree Fahrenheit below the preset temperature of lower set controller 16, that controller energizes its electromagnetic switch and lead 24 to motor 23 is energized and causes motor 23 to rotate in a clockwise direction which it continues to do until the temperature rises to or above 1 degree above the preset temperature of the lower set controller 16, whereupon the controller 16 then breaks or de-energizes and -opens switch to the lead 24 and the motor stops; if and .when the temperature rises to or above one degree Fahrenheit higher than the higher preset temperature controller 16, that controller breaks and de-energizes, where with the other controller already de-energizes at a lower temperature, and the like pole there already closed, the circuit through lead 25 is closed to motor 23 which begins to rotate in counterclockwise direction which it continues to do until the temperature falls to or below 1 degree Fahrenheit below the higher preset temperature controller, then reaching or falling to the temperature the controller again energizes its switch 18, whereupon the movable contact is opened to lead 25 and motor 23 stops; thus results higher preset temperature controller controls for counter-clockwise rotation of motor 23, and the lower preset tempera-1.

ture controller controls the clockwise rotation of motor 23, with the impossibility for both controls to operate simultaneously, and where both of leads 24+25 are open circuit when one controller is energized and the other controller is de-energized, with the intervening temperature hand between the two control points providing no motor action, and, thus, becomes the found band for stabilization of controller depicted in FIG. 8 which is represented in box 21 in FIG. 1. Motor 23 as shown in FIG. 10, as previously shown in FIG. 8, may drive pinion gear 35, and, in turn, drive ring gear 34 and rotate thread ed shaft 32 and move contact arm 33 to the right, or left, laterally across the switch positions of the program switch, FIG. 10, and the array of contact strips to switch .on or off singly, in various combinations, contact strips, and control leads, 26, 27, 28, 29, and 30 from the current supply on bus bar 31, to actuate respective one or ones of electromagnetic power switches 124 in FIGS. and 16 of the respective circuits of parallel connected coils, where each coil in a circuit, as shown in FIG. 16 is of the same wattage capacity but with a schematized variance in wattage rating of coils between that of one circuit and that of another circuit. As an example, as shown in FIGS. 15 and 16, the circuit with the lowest rating, 12a of X watts, 12b 2X watts, 12c 4X watts, 12d 8X watts, and 12e 16X watts, with control leads 26, 27, 28, 29, and 30 respectively controlling electromagnetic power switches of these circuits of heaters, and an array of contact strips from which these respective control power leads 2630 come, are positioned in such a manner across the face of the program switch 10, that, starting with each switch position (for contact striparm 35) starting with the off position, where no contact strips are positioned, to the next right position with a strip for 12A circuit only positioned, each succeeding switch positioned to the right have contact strips positioned either singly or in combination with each other, to, by manipulating electromagnetic power switches 124 in FIGS. 15 and 16, increase wattage output switched to an array of electric heating coils in one heating location or heating jacket by X watts for each switch position step by step through thirty-one switch positions, from X watts up to 31X watts for the last switch position, thus to implement a method of increasing or decreasing wattage output in clusters of heaters by moving, in a temperature responsive power driven way, the contact arm 33 to the right or left, and thus increase or decrease gradually X watts at each change of switch position of contact arm 35, and without interrupting a continuous heat generation. Provision must be made in the gear ratio between motor pinion 35 and ring gear 34 for the threaded shaft to turn slowly enough to move contact arm 33 slowly enough from one switch position, for heating elements turned off to cool, and these heaters turned on to heat and sensors to register therefrom before the next switch position involved is reached.

The program switch, as shown in FIG. 10 with its movable contact arm 33 as positioned temperature responsively from action of controller as developed in FIG. 8,

through control motor 23, transmits temperature response on a reaction basis to determine the output of heat generation through a system of variable heat generation, with use of electric heating elements as shown in FIG. 15 of schematized variance in wattage ratings, one element from another, as located together in one heating jacket so as to act singly, any one of them, or to act in various combi nations of heating elements, as finally controlled by the program switch of FIG. 10 as represented by box 37 in FIG. 1. Details of elemental operation of the variable heat output generation is shown in FIG. 15, where the instrument of control is the remote control of respective electromagnetic switches 124 by the program switch FIG. 10 (or box 37), through contact strips as arrayed on the switch face, through control power circuit lead-s 26, 27, 28, 29, and 30, where any variation by X watts input can be switched in by signals or combination switching in and out of electromagnetic power switches 124 which brings about heat output variances from X watts to 31X watts, X watts at each step by individual and combination actions of heating elements 12a, 12b, 12c, 12d, and 12e.

In the lower portion of FIG. 16, an extension is made of the system of variable heat output generation as developed in FIG. 15 to plural heating jacket locations involved in one heat control entity, with circuitry arrangement for distributing power load by full powered heaters, one or more heating elements; to each phase each having three one-third power heating elements for each circuit divided one each for the three phases: power leads 51 and 52 comprise one phase, 52, and 53 another, and S1 and 53 the final phase. Control leads 26, 27, 28, 29, and 30 and all five respective sets of electromagnetic switches 124 taken together are represented as box 38 in FIG. 1. The upper portion of FIG. 16 shows thermistor sensing details 20 and 22 as developed in FIG. 8 extended to the operating location in the oven control system, but each pair of thermistors 22 are represented as control lines, viz. 40, 42, for heat generation, and 39 and 41 for air flow regulation. Heating elements and these control lines are shown graphically in drawings where they are used.

Based upon characteristics of the oven and its circulatory system as shown in FIG. 1, as heretofore related point by point where it is shown that air can be circulated through and dispersed evenly within the oven enclosure, and based upon the coincidental even dispersal of heat by equal capacity of, and even generation and delivery of heat, one inch with another inch, along the length span of each of the heating jackets through which the circulating air passes, and based upon the fact, therefore, that no storage of heat can occur anywhere in the operating part of the oven since it cannot build up to any temperature level higher than that of the heated air itself with which it is in constant heat exchange and based further upon the facility for varying heat generation up and down by use of plurality circuits of heating coils, and a program switch controlling same from temperature sensing responses, as interpreted by sensing control system as shown in FIG. 8, which has also been related heretofore, and based further upon the facility for increasing or decreasing the rate of flow of air circulation through the oven as controlled by a variable resistor system as shown in FIG. 14, in series with the power feed to the fan motor propelling the fan from temperature sensing responses as interpreted also by a duplicate unit of sensing control system as shown in FIG. 8, a method can be provided for a compound temperature sensing response operation of varying both the volume of circulating air and the volume of heat generation in relation to each other, which can be employed to automatically supply the volume of heat required to maintain a stabilized cooking process of a given mass of meat (as loaded in the oven) or other cooking objects, at desired temperature levels, as preset for the high and low temperature points, namely the beginning temperature and the ending temperature of the air in its passage around and by the meat or other cooking objects. Controls for employing this method are partly provided inside the oven as shown in FIG. 1 and partly provided by auxiliary components used and controlled outside the oven as shown in control board 105 section of FIG. 1 and can be described as follows:

Three interconnected control units are shown together in group 120 namely boxes 21, 37, and 38 for control of heat generation by lower level series of heating jackets as shown. The first box 21 as shown in the block of the same number and in detail in FIG. 8 receives sensing signals from two thermistors 20 where the two of which are shown together as a block 22 in FIG. 8, but now are particularized in one suitable control line as numeral 40 to show the extension of the one pair of thermistors to desired locations as in FIG. 16 and FIG. 1 where each thermistor is cross-matched and balanced as necessary by compensators for use with an individual controller 16, where 40, an assembly of two such thermistors and their four circuit wires is placed in the lower compartment with meat between it and then heating coils in the lower section heating the air, as shown in FIG. 16 and FIG. 1 to sense the ending temperature of the air after it has passed the meat, when air moves upward in the oven; and 42 as placed in the lower compartment with the meat in that compartment between 42 and the heating coils in the upper level of heaters, heating the air when air is passed downward through the oven, to sense for ending temperature of the air after it has passed the meat in the lower compartment. One section of hand switch 46 determines the appropriate lead off of 40, to be switched to controller 21 as interlocked in same switch, as it switches in also the appropriate power lead 43 or 44 to fan motor 9 for the right direction of rotation of the fan motor to pull air upward or push it downward through the oven. The power lead 43 in FIG. 1 for fan 8 rotation to pull air upward, or power lead 44 to reverse fan rotation to push air downward, as the third lead 15 from fan motor 9 is to ground to complete the circuit. The second box 37 in control group 120 contains the program switch, shown in detail in FIG. 10 where the contact arm is moved back and forth by motor 23 in box 21 of the same group 120, to manipulate switching control current to leads 26, 27, 28, 29 and 30 as shown in FIG. 10 and also in FIGS. and 16 which extend in box 38 of same group 120, which contains power-in leads to circuits of heating coils 12a, 12b, 12c, 12d, and 12e also contains electromagnetic switches 124 in FIGS. 15 and 16 actuated by control leads coming from box 37 to energize heating coils 12a, 12b, 12c, 12d, and 12e of respective circuits, and thus provide the controlled heat generation.

To describe the joint temperature sensing response control of the volume of air flow by varying the speed of the fan: Air temperature is sensed for a preset temperature level at its initial temperature after leaving the heating jackets and before striking the meat by sensing unit extension 39 of sensors in lower compartment which are associated with sensing control box 21 in group 122, where its motor 23 by pinion drive 131, FIG.l4, moves arm contractor 128 across linear resistance all contained in box 38a in group 122, and as shown in detail in FIG. 14 to lengthen or shorten resistance and vary speed of fan through lead 39 which passing to section of interlocked switch 46- to be alternately switched to lead 43 or 44 going to fan.

Using the lower cooking compartment as the space to be jointly heat controlled by both heat generation and air flow, when air flow is upward through oven group of interconnected mechanism boxes 21, 27 and 38 which are involved with the lower level heating elements, containing one coil of each of the five circuits 12a, 12b, 12C, 12d, and 12e of varying wattage capacities for coils 12a, 12b, 12c, 12d, and 12e respectively as shown in FIGS. 15 and 16 in each one of the four separate heating jackets, and sensed for heat generation (variation) by sensing circuit 40; while simultaneously and conjunctively use of group 122 of interconnected mechanisms boxes 21 and 38a which are involved in regulating the speed of fan motor 9 and fan speed and rate of flow of air from fan 8, is sensed for fan speed regulation by sensing circuit 39 gives a total situation where sensing unit 39 is controlling for the initial temperature of air before it strikes the meat, and sensing unit 40 is controlling for the ending temperature of the air after it has passed the meat, and has had heat withdrawn therefrom by the meat. The method of compound temperature sensing response control of the above described operation is as follows:

The initial temperature for the air fiow before striking the meat is preset in variable resistors 17 of box 21 in group 122, and can be any temperature level desired for the resulting cooking effects, and the ending temperature of the air after it has passed the meat is preset with variable resistors 17 at box 21 of group 120, and can similarly be any temperature desired, though necessarily some little or considerable lower than the temperature level preset for the initial temperature, to provide for withdrawl of heat from the air stream by the meat, for cooking results also, such as crusting, overcooking and undercooking, etc. In this method of heat control, varying the air volume or relating mass of air to heating elements delivering heat thereto becomes, in reality, a temperature control of the air stream, while varying the amount of heat being generated becomes in reality the heat volume control. Thus, with a system of out-going heat delivery, with no heat storage in metal possible, this compound temperature sensing response operation controls the volume of heat on an absolute basis at these temperature levels which is delivered to and absorbed by the meat or other cooking goods.

The amount of heat volume which can be absorbed by any given mass of meat would, of course, vary upward or downward with the temperature levels at which the heat is delivered to the meat. With any given preset temperature levels for initial and ending temperature of the air volume, the meat will continue to cook with the controls both air volume and heat generation varying under the temperature sensing response system to produce the volume of heat being absorbed by the meat at these temperature levels so long as the meat is able to absorb enough heat from the gradually decreasing volume of both air volume and heat generation to effect the drop in temperature levels between these two beginning and ending temperature points. When heat generation and air flow both can be observed to have dropped drastically, the controllers and power feed through the electromagnetic switches to motor 23 controlling the fan speed can be cut oil, whereupon the fan speed and air volume will remain fixed at this point thereafter, and the meat cooking process can continue until the initial temperature drops gradually to approach the same temperature level as that for the ending temperature until meat is done.

Safe cooking at low heat is possible when the ending temperature at point 40 is down to the lowest temperature and heat level which will still prevent the multiplication of bacteria cultures involved in the spoilage of meat, as this is the lowest temperature level in the oven.

The compound temperature sensing operation can be maintained in either the lower cooking compartment with air flow in either direction, or in the upper compartment with air flow in either direction, but not in both simultaneously, by manipulation or switching of switch 46 sensing units and direction of fan rotation as follows:

Group 120 involved with the lower level of heating coils, and with sensor circuits associated therewith, is operable for cooking in the lower compartment with sensing unit 40 operating therein when air flow is upward in the oven, and is operable for cooking in the upper compartment with sensing unit 40 operating therein when air flow is downward in oven. Group 121, which is an exact duplication of the mechanisms, interconnected, of

that for 120 with sensing units 42 associated therewith,

is operable for cooking in the upper compartment with the sensor circuit 42 operating therein, when air flow is upward in the oven, and is operable for cooking in the lower compartment with sensor unit 42 operating therein when air flow is downward in the oven.

Group 122 with interconnected mechanisms in boxes 21 and 31a in FIG. 1, with sensor circuits 39 (and 41 associated therewith) will control the volume of air flow in accordance with the temperature setting preset therefor, and as sensed at any one of the two sensing units 39 or as sensed at any one of the two sensing units 41. 39 is designated for use when air flow is to be upward, and 41 is similarly designated for use when air flow is to be downward.

The direction of flow of heat upward can be reversed to downward flow with sensors interchanged for proper cooking operation by manipulations as follows: As air flow can be sensed at one point only, all eight thermistar sensing units associated with box 21 in group 122 lead in to hand switch 45, and as separate units, namely 39 and 41 as placed in the upper cooking compartment, and 39 and 41 as placed in the lower cooking compartment. Use of two position switches 45, interlocked will switch in 39 and 41 respectively of upper cooking compartment when thrown to one position, will switch in 39 and 41 respectively of the lower compartment when thrown to the other switch position, to select whichever one of the two cooking compartments is to be used for joint control for heat generation, and extends such circuit connections to hand switch 46, interlocked not only for the air flow sensor units but for upper and lower level heating coils, and circuitry for controlling the direction of fan rotation, and air flow, also is a two position switch 45 which when thrown to one position interchanges all sensor connections and fan rotation circuit in such a manner that only one sensing unit of air flow as proper for joint sensing operation for that air flow is switched in for the control cooking compartment as previously selected by switch 45 and proper sensing unit for heating coils upper or lower for proper air flow (upward or downward) for both cooking compartments, and thermistors in the fan motor lead also for proper fan rotation and air flow, all by upward flow for one switch position of 46 and downward air flow for the other switch position of 46.

With joint sensing operation for air flow and heat generation switched to either one of the two cooking compartments, it cannot, of course, operate for the other one of the two compartments. On the other hand, air flow as it is controlled jointly with heat generation in one compartment is fixed for its flow through the other compartment. Heating coils operating for the other compartment with ,proper sensing unit at proper sensing point can react to compartment, when the heat absorption capability of the meat in the non-controlling compartment will be approximately the same as that for the controlling compartment, and the beginning or initial temperature level for the air before striking the meat in non-controlling compartment, will be approximately the same as for the controlling compartment, but, however, the meat mass is larger in the non-controlling compartment, more heat will be required to maintain common ending temperature, hence the initial temperature in that non-controlling compartment will be higher than that for controlling compartment, or if meat mass is less and heat absorption is less for non-controlling compartment, then the initial temperature of the air flow in this compartment will consequently be less than initial temperature of air flow in controlling compartment.

Referring now to the drawings showing fabrication and structural aspects of the oven:

FIG. 2 shows at 99 the exterior metal casing of the boxed-in oven having a door 110 opening out from one side thereof, and containing a glass window 111 and having mounted at one side a control board containing control components as shown in detail in FIG. 1.

As shown in FIG. 7, flexible heat insulating material 112 is laminated between outside metal casing 99 and inner metal surface 100. Partitions 101 and 102 are spaced apart from the inner side wall at either side, and extend horizontally from front to back, with top edges spaced apart from inner metal surface of top of the oven to provide air passageways, and similarly having lower edges spaced apart from inner metal bottom of oven to provide air passageways, except that one edge of partition 101 extends sufficiently below the edge of partition 102 to make a right angle juncture with separator plate 109, where 109 extends and bounds air channels 1 and 2 formed between spaced apart partitions to respective ones of the bottom row of heating jackets. Partitions 101 and 102 are detachably positioned from inner back of oven.

A series of battle plate drain troughs and heating jackets 5 and 6, each running or projecting from back to front are arranged in a row along a horizontal level, and spaced apart so that a heating jacket enclosure 7 is partially enclosed by each two.

The two inner partitions, 102 each running from front to back, at each side of cooking compartment, make each a right angle junction with fan plate 103 as shown in FIG. 13. Fan plate 103 has a cut-out for fan travel and separates the cooking compartment from the air head above the fan, and functionally prevents any back flow of air contained in this air head back down into the cooking space, adjacent baflie plates and with air passageways openings one at top 4 and one at bottom 3 of heating jacket so formed, with each unit of bafilie plates so constructed as shown in front view in FIG. 5, where top wing troug'h 6 may catch and contain or drain grease and liquid drippings where the right side of wing extends up over and overlaps the opposite of the wing of adjacent trough, and is a metal casing having an inverted downward winglike 'heel 5 extend outward in either direction to act as a shade for heating elements enclosed in 7. Interposed between outer metal trough 6 above and 5 below and inner metal surface 107 of the heating jacket is a layer of heat insulating material 106 to prevent the transfer of heat from heating elements either by through-metal conduction or radiation. Each baffle plate unit extends on cantilever from back where it is detachably positioned in the oven back. The bottom row of bafile plates opens directly into individual air channels 1 or 2 through aperture 3, and open upward into oven, where another row of baffle plates are superimposed from the back of oven along a horizontal level higher in the oven. Each heating element assembly in heating jacket 7 contains one or more electric heating coils 12 each coil with individual terminals for circuit connections mounted in suitable ceramic and metal sheathing, is mounted in a threaded manner with screwdown bolts in back plates of oven and extends frontward through enclosure 7 makes a hair-pin bend and back to mounting as shown in FIGS. 4, 9, and 12.

Fan 8 is rotatably mounted in the center top of the oven in a manner to pull air upward, or downward through oven to or from air channel 1, 2 spillways, and traverse the traverse circular span of the oven in which the cooking area is of equal width and depth. Fan plate 103 as shown in FIG. 13 extending front to back along one horizontal level and making right angle juncture with inner partitions 102, has a cut-out to circumscribe and bound fan blade travel space and thus separate upper fan head space opening into air channels 1 and 2 and the main oven space.

FIG. 3 is a vertical view of top side of the troughs and heating jackets with positioned heating elements extending thereunder as taken on line 33 of FIG. 2 and shows the four troughs overshading the four respective heating jackets located on one horizontal level.

FIGS. 6 and 6a show top plan view taken vertically of the inner oven space with fan motor 9 and control board 105 attached to the outside, and shows meat 11 as mounted on rods 59. These views are also taken on the 6--6 of FIG. 2. Meat may also be positioned in cooking space on insertable racks 60 as shown in FIG. 1.

FIGS. 4 and 9 show the mounting of electric heating coils. Details covering two such heating elements show the manner of mounting plural elements even though the number of such elements may be as many as 5 or more. Moreover, actual heating coils may in plural numbers be mounted within one metal sheath, viz: the three lower rated coils X, 2X, and 4X may be enclosed in one metal sheath, while coil-s of rating 8X and 16X may be enclosed in the second metal sheath.

A modification may be made of this oven and heat control system using the intervalized positions for heat generation, or heating jackets, in the manner described to heat-treat cooking, or for the heat treatment of goods with horizontal charges of heated air, controlled in the same manner as for vertical travel of air. Such a modification consisting of metal bafile adapters running from front to back in cooking or heating space and across, sideways to make a junction with a heating jacket in which plural heating elements, controlled in same manner as shown in FIG. 1, may be effected in the same oven enclosure as shown in FIGS. 1 and 7 by provisions for mounting bafiie heating jackets and heating coils.

The essentials of such a heating system employing side to side delivery of heated air are shown separately in FIG. 11. Two partitions 117 separate cooking space from oven inner metal 118 and form two air channels 119 running from front to back, and running vertically to form the two sides of the cooking space. Metal baffles, adapters 113, run front to back horizontally and likewise across each respective level, taken to make a T or right angle junction, with insulated heating jacket 116.

Heating jacket 116 consists of two spaced apart insulated sides, running horizontally from front to back of the oven enclosure. The corner side 115 with insulating material between inner metal surface 116 and the outer metal surface which makes a corner junction with the side of partition 117, and the next succeeding upward metal baflle 113, while the inner section of the insulated side of heating jacket 114 with its inner metal surface 116 spaced apart from that of the side 115 to form heating jacket 116 in which heating elements 125 are positioned from back to front of the oven, and through which such formed heating jacket moving air is passed around said heating elements 12, from one level formed by metal bafile 113 and the next lower, or higher such metal baffie 113 below or above it, where the air pulls around between two adjacent metal bafiles 113 and their respective adjoining heating jackets 116 positioned at alternate sides of the cooking space from one cooking level to another as pulled upwardly or pushed downwardly by 12 fan 132 to make one circulatory cycle after another and as regulated by temperature responsive fan motor speed control by same system as shown for boxes 21 and 38a in FIG. 1, group 122, where heat generation is varied up and down with plural circuits of plural heating elements 12 located one element 12 of each circuit in each heating jacket, by same combination of boxes 21, 37, 38 in groups 120 and 121. Motor means is provided to drive fan 132.

The control mechanics of cooking, or heat treating with these particular controls are as follows: An array of uniform heating elements as showtn in FIG. 16, are positioned to protrude from back to front in each heating jacket shown in FIG. 11, where each jacket is formed by the inner metal surface 116 of insulated bolster 114 joining in the end of metal 'bafile 113, and the inner surface 116 of adjacent insulated bolster 115 jammed as molding against the side or partition 117 and the next upward succeeding metal baflle 113, as the heating jacket so formed makin a degree circle bend from lower vertical opening or aperture 123, to exhaust, when air in upward flow, in a horizontal direction through upper opening or aperture 124, where each such heating jacket runs front to back of the oven structure making a right angle junction with back of the oven. These heating elements of schematized wattage rating variance as shown in FIGS. 15 and 16, with variable heat generation effected by respective electromagnetic power switches 124, as manipulated by the program switch as shown in FIG. 10, in response to two temperature point sensing as developed in FIG. 8, with sensing heads A and B as shown in both FIG. 11 and also in FIG. 12.

FIG. 12 is a top view of the metal bafile 113 and adjacent heating jacket 116 taken on the line 12-12 of FIG. 11. When air is passing in the updraft direction through the oven structure, air is leaving the lower cooking level to be heated according to sensing controls, one set for regulating the flow of air (fan speed) as located at A in both FIGS. 11 and 12, for initial or maximum temperature, and the other sensor located at B, set to control the regulation of heat generation at the ending, or minimum temperature, as the heated air passes across the top of the meat, baking goods or other heat treatment goods such as metal or textile strips to proceed upward through the next aperture 123 and heating jacket and out horizontally in the opposite direction in the cooking level above. In the case of meat or baking goods held in pans as positioned on metal baflle 112, they receive heat by through metal conduction from said metal baffle 113 which is in heat exchange relation with air passing through the cooking level just below, as has been similarly heated in next previous heating jacket 116. Dotted lines 61 in FIG. 12 outline the space occupied by baker pans. If air is downdraft, then B becomes the control point for air flow, and A the point for control of heat generation. All heating coils in each respective circuit are of the same wattage rating and located one element in each heating jacket, and as connected parallel can be controlled by one respective electromagnetic switch 124, for each of five circuits.

This oven control system, including its provision for even heat generation and dispersal, and the compound sensing system, controlling both the volume of heat generated, and the volume of air flow to which the heat is transferred as a heat changing medium, may be utilized to provide even heat delivery, and to insure against both overeheating and underheating in post-curing or deferred curing of textile garments or piece goods containing synthetics and impregnated crosslinking additives such as resin, sulfone chemicals or other finish additives, wherein said textile goods, properly positioned in the heating space, instead of meat, or other food goods, as hereto described are exposed to heat treatment.

An embodiment of the essentials for such operation, and including special structural arrangements intended to overcome some of the shortcomings presently experienced in conventional ovens, are as follows: Plural units 199 in FIG. 17 each of which is an entity, as shown in FIG. 2, are placed contiguously in series with one another, front to back, and with each back wall 99, as shown in FIG. 6, and with each door 110, as shown in FIG. 2, as intervening between any two of the units 199 removed, so that one unit 199 opens directly into the next unit 199, and where the completed configuration, as shown within the solid lines in FIG. 17, consists of plural cells or cubical spaces 199, as indicated by dotted lines as subdivided cubical spaces, where each such cell or cubical space contains a complete heat generation and control assembly as illustrated in FIG. 1 and FIG. 6; or where, as an alternative, each cell or cubical space may contain a heat generation and control assembly as shown in FIG. 11 and FIG. 12, but where either one of these heat generation and control assemblies is operationally augmented with control devices as illustrated in FIG. 8, FIG. 10, FIG. 14, and FIG. 16, so that the system will operate individually within each said cell.

Such an assembly of individually operating units 199 may have textile goods batch loaded therein for exposure of textile goods to heat treatment at a uniform temperature level in all cells, but where, however, the temperature level may be progressively raised and then lowered during predetermined stages of the curing process.

An alternative method may be employed to accommodate the progressive movement of textile goods, properly pre-positioned, successively to and through each respective cell by means of a moving conveyor system 212 as shown in FIG. 20, where each respective succeeding cell, or cubical space may employ a progressively higher or lower tempertature level for heat treatment, viz: 199a at temperature 1 plus y; 199b, at t plus 2y; 1990, at t plus 3y; and 199, at t, where t represents the ambient room temperature and y represents a fixed temperature value as expressed in a given number of degrees Fahrenheit, i.e.: 50 degrees F.; 75 degrees F., 25 degrees F.; 40 degrees F. etc., 100 degrees F., etc.

This progressive application of heat intensity to textile goods, amounting to a tempering process, results in a more gentle or softer application of heat treatment to effect a bonding of cellulose molecules by resin or sulfone or other chemicals into a permanent shape at lower maximum temperature peaks than those usually used at present, the lowest of which appears to be 320 degrees Fahrenheit for 8 minutes exposure. This lowered temperature peak results in less deterioration to cotton fiber by heat, and consequently results in a lowered requirement, percentage-wise of synthetic fibers in the fabric blend, as imposed especially to reinforce for the resulting damage to cotton fibers from higher heat; and higher heat peaks results, additionally in a requirement for a less amount of resin, sulfone, or other chemicals, imposed especially to bond the cellulose fibers of both cotton and other synthetic fibers. A 50% reduction in tensile strength damage to cotton fibers from heat is commonly accepted under present curing procedures. This tempering method should permit complete curing or bonding at a peak temperature as low as 250 degrees F., and perhaps down to as low 225 degrees F. The lower damage to cotton fibers will improve the shape memory of the garment, as well as the wearing quality of the finished product, and should result in a lower amount of shrinkage than now accepted under present methods of curing.

In operation, if heat treatment using the progressive change in temperature levels, cell by cell, where basic materials cellulose and resin or other chemical ingredients, results in an energy exchange as the molecular bonding occurs under heat treatment to an extent that some heat input is still required in each cell 199, where its temperature level is lower than that of the next preceeding cell, for this bonding to occur, there is no problem in using normal heat and air controls in the cell with a lowered temperature level. However, the use of the tempering process, and is resulting lowered peak temperature level the goods have undergone, is intended to lower the amount of energy exchange involved in the bonding process, and thus to lower the degree of deterioration or disintegration of both fabric and dyes.

Thus, achieving the desired end of minimizing the energy exchange, the heat treatment tends, more and more, toward a heat exchange between the textile goods and the heated air swathing them, whereby the textile goods thereby serves more and more as a heat sink for the temporary storage of heat. It may become necessary, therefore, to simultaneously partially or fully exhaust heated air at the top of the cell, and to partially or fully intake the cooler air at room temperature. Thus, such a partial or full exhaust of heated air is made through exhaust port 200 in FIG. 17, while at the same time, partial to full intake of cooler air is made through an intake port similar to that for the exhaust which may be located at the bottom of the cell (not shown) or through smaller intake ports distributed at intervals within the cell, thus, to disperse the cooler air properly to all textile goods in volved in the cooling-down process. This valve control operation for such parts is temperature responsively ac tuated by movements of the contact arm as illustrated in FIG. 14, or as illustrated in FIG. 10 and as the fan speed is also simultaneously controlled therewith.

Plural units 199, or cells, may be contiguously arranged side by side, as well as front to back in rows as illustrated in FIG. 18, where solid lines outline the completed configuration, and dotted lines indicate subdivided spaces therein, and as shown cross-sectionally in FIG. 20 and in perspective detail in FIG. 22. Such an arrangement of cells, with each section of subdivided spaces side by side having its own individual heat generation and control system, a front view of which is shown in FIG. 19, and as it may be imposed within existing oven shells already in place in using establishments to effect the necessary conversion for heat treatment of textile goods in accordance with the conditions outlined, and procedures prescribed, in the foregoing.

In the operation of the compound sensing control of both heat generation and air flow in the step by step heat treatment of textile goods, particularly in using the tempering methods, it would be well to set the temperature level for the ending temperature (minimum) ten degrees F. below that set for the initial (maximum) temperature needed in each cell. The tempering process as applied to present blends and additives presently used in deferred curing of stretch denim, would be as follows:

Use seven cells 199 as described above, where the movement of goods 211, as suspended on hangers from the cross bar of the moving conveyor 212 as shown in FIG. 20, through each cell 199, will require the same amount of time; use degrees F. as the value of y, and, starting with the ambient room temperature of 75 degrees F the stepped-up temperature in the first cell 199a where the textile goods 211 are first exposed to heat treatment, will therefore be at 170 degrees F.; the next cell 19% will, therefore, be 265 degrees F.; and the next three cells 1990 will have a constant temperature of 360 degrees F.; and the next cell 1991) will have a droppeddown temperature of 265 degrees F.; and the next, 199a down to 170 degrees; and the final cell, 199, at room temperature of 75 degrees F. Travel time is fixed at 2 minutes through each cell. Here textile goods have an overall heat-treatment exposure at 170 degrees, or above, of 14 minutes; and 10 minutes at 265 degrees F. or above, and at peak temperature of 360 degrees for a total of s1x minutes.

An alternate procedure which should result in less deterioration for some other types of textile goods using a different blend, with less synthetics and resins of bonding chemicals, can be as follows:

Use 75 degrees F. as the value of y, where the first cell, 199a will be at degrees F.; and the next cell 1991;

will be at 225 degrees F.; and the next three cells, 1990 will have a constant temperature of 300 degrees F.; and the following cell 19% will have a dropped down temperature of 225 degrees F and the next cell down to 150 degrees F., and the final cell a troom temperature of 75 degrees F. Travel time is fixed at 2 minutes through each cell. Here textile goods will have an overall heat treatment exposure of 14 minutes at 150 degrees F. or above; and minutes at 225 degrees F. or above, and at a peak temperature of 300 degrees F. for six' minutes.

As initiative in revision of blend formulas follows full be no underheating and/or overheating in the tempering method below or abave the range from initial and ending temperature of air pasing around the textile goods to transfer heat thereto, blending mixtures and bond additives should be lowered to make full use of the tempering heat exposure in seeking longer wearing life and better shape memory of textile garments, and a suitable procedure doubtless will be as follows:

Using 58 degrees as the value of y, and starting with an ambient room temperature of 75 degress F., the first stepped-up temperature in cell 199a will be at 133 degrees F.; and the next cell 1991; will be at 191 degrees F.; and the next three cells 1990 will have a constant temperature of 249, or 250, degrees F.; and the first dropped down temperature in cell 1991: will be again at 191 degrees F.; and the next cell 199a down to 133 degrees F.; and the final cool-01f cell 199 at room temperature of 75 degrees. Travel time is three minutes in each cell. Overall heat treatrnent at 133 degrees or above 21 minutes at 191 degrees 12 minutes and at peak temperature of 250 degrees 9 minutes.

A satisfactory conveyor system may be partly shown in FIGS 20 and 21, where the conveyor consists of a plurality of cross bars 212 which extend laterally across the heating space, and which are linked together with the sprocket link chain 214 at each side, and where the sprocket link chain also passes over two driving sprockets actuated by aiding a driving motor impelling movement of the conveyor rods or bars through the cells, also not shown. Each cross bar has a freely turning roller at either end, and fashioned to be partly encased in supporting rack 213 as aflixed on the side wall of each side of the heating space in successive heating cells. The bars pulled by link chain 214 with racks of textile goods 211 suspended therefrom as shown in FIG. 20 pass into and move through each cell, a front cross-sectional view of which is shown in FIG. 20 where textile goods 211 move backward through successive cells as the bar (one of the plural bars) moves along the lower rack rail 212 on each side of the heating space to support textile goods 211 in prefixed position, as heated air passing around heaters 12 receives heat at the fixed temperature levels and air flow speed necessary to maintain these temperature levels and impart heat to moving textile goods 211 at these prefixed temperature levels. Conveyor bars 212 with textile goods removed therefrom return in lapped-over manner in rails 213 in FIG. 21, as shown in FIG. 22 to complete the convey cycle over again.

In any one of the three procedures outlined above, the result is a lower heat exchange impact by the textile goods initially, where each step, in the step-by-step procedure in the heat intensity build-up serves as a preheating stage for the next succeeding cell, and as a pro-cooling stage in the cooling-down cells; and this results in a requirement for a lowered rate of air flow in all cells, and in a more constant heat absorption rate, in B.t.u.s per minute by the textile goods during the entire curing process.

More specifically, in the step by-step build-up of heat intensity, cell by cell, the textile goods are preconditioned, heat absorption-wise, in each cell for the receipt of additional heat intensity to be imposed in the next coming cell, in cell by cell stages, from ambient temperature on up toward the lowest heat intensity necessary to induce the bonding process of the fibers in the fabric of the garments. And, here, heat intensity is determined by both the temperture level and the depth of the intensity as measured by the volume or flow of air involved in heat delivery. After undergoing heat treatment at constant heat intensity for the minimum time interval required for bonding, as the garments proceed through the step by step cooling down stages, the brief interval of time in each stage permits some seasoning of the bonded fibers at progressively lowertemperature, stage by stage, than that having been reached for bonding, on down to room temperature.

In such a process, this oven system can insure correct adherence to prescribed procedures by textile goods in quantity; the provision for even heat generation and dispersal by and through evenly dispersed flow of air for delivery to goods of primary heat permits no shading or starved or depleted heat depth delivery to goods to result in underheating, except as provided for in differential sensing and permits no uncontrolled delivery of wild heat from uncontrolled sources to result in overheating; and the compound sensing for control of both volume of heat generation and the flow or volume of air medium to which the heat is related, senses and proportions the exact amount of heat intensity required in each cell, with the heat control in each cell completely independent from that in any one of the other cells. This provides flexibility for adding to the number of cells from the number of cells outlined above to fix breaks in the heat intensity levels at lower values of y, for formulating, processing heat level and time interval-wise as necessary, for various purposes or results, and for various blend mixes, as it provides strict adherence to the predetermined formula for which the controls are preset.

If a ten degree differential between the initial, or maximum, temperature level, and-the ending, or minimum temperature level, is used, it is intended that the initial or maximum temperature level be set at 5 degrees F. above the temperature level stated for each cell, and the minimum or ending temperature level be set at five de grees below this stated level.

FIG. 21 is an expanded cross-sectional view of one cell 199 as shown in FIG. 17, with fan 8 positioned therein as well as air return channels 201 and 202 going to respective heating jackets 7, with garments 211 positioned to suspend on hangers from conveyor rods 212, each rod with the roller at each edge held in supporting rail 213 along each side wall of each heating cell, where these cross rods are linked together with sprocket chain 214 (or 215), as shown in the vertical or top view of section of conveyor in FIG. 20, as is shown operable in perspective view of the interior of each cell 199 as shown in FIG. 22.

FIG. 19 shows a consolidated space arrangement for an arrangement of four cells abutting transversely as shown in FIG. 18, with the side walls removed and space for air channels at each edge of the resulting structure, and with four axial type fans operating contiguously through fan plate 103.

The cell arrangement stage by stage, increases in heat, pick up again on even heat dispersed and instant response cell by cell arrangement providing two valuable flexibilities.

(1) In changing value of y for internal purpose results.

(2) Together with compound sensing designed heat volume for the required heat volume for goods as they are in each cell, each instant clearance designed aagin to change with garment weight and size as soon as changed garments reach sensing space.

As to the physical resin bend slight period at each receeding heat levels allows a brief seasoning period in each cell for newly formed physical blend bend.

Heat treatment may be renedered by a tempering method to metals, ceramics, wood, lacquers etc., either in fabricated objects or piece materials in a method to prevent unintentional or accidental underheating or overheating by use of an individual compound sensing and heat control system in each of several subdivisions of a heat treatment oven-like over structure, wherein each such subdivision is positioned in a series arrangement with other such subdivisions in such a manner that procedurally predetermined stages of heat treatment may be effected in an ascension of heat intensities, an individual intensity for each such subdivided space, where each such space serves to preheat the product, which is moved through the succession of subdivided spaces on a slideable conveyor, preparatory to receiving a higher heat intensity in the next succeeding subdivision, until lowest product peak heat stage is reached, then holding peak heat stage in a time cycle according to the number of subdivision spaces required at a given rate of travel therethrough by conveyor system to complete peak heat treatment, and thereafter deheating product in descending stages, one subdivision for each deheating stage until the product is brought back to room temperature. With sensors located in the terminal portion of product travel path in each subdivided space to control on temperature differentials as set, for product heating at control point, sensors extend dynamic control in a manner as follows; even heat generation as controlled for product heat condition at point of control, where sensors are located, to impart to product units moving from entrance into unit structure, or subdivision, to point of sensor location, heat at an even volume although product heat is gradually building up therefrom in its movement through the structure, wherein said even heat supply forces environmental temperature, of the air medium, upward in a grdaual manner along with, and just above, that of the gradually rising product heat level, thus to transfer heat evenly and in a tempering manner to said moving product units. Temperature and heat levels may be used as required up to the limit of heat levels for which the fan operation and transmission of heat by air or other vapors can be made to function. Many such uses as baking pottery, heat treating aluminum, drying and baking paints, and enamels, or various types of steel products may be accomplished at greater precision of heat control and at improved effeciencies otherwise such as adequate heat treatment in a shorter over-all time period, less shrinkage and other imperfections and may be accomplished in a manner as described above for textile garments and products. Where heat and temperatures required may be for 1000 degrees F. or higher, special steels and alloys may be used for fan ma terials suflicient to withstand higher temperatures, and special metal or alloy or ceramic materials may be used for inner surfaces, baflles, etc. Certain specialized types of thermocouplings, and/or bellows type thermostats may be substituted for thermistors as sensing elements Various types of insulating materials suitable for higher heat levels may be used, such as ceramic or refactory insulating materials for inner surfaces, in combination with special type of glassin bubble form, where the objective is both to conserve heat within the enclosure and to protect the temperature in the room in which oven structure is located.

The compound sensing system for regulating both the flow of air and the volume of heat generated, for initial and ending temperatures of the air flow as it is to pass around heat treatment objects and transmit heat thereto may be used where heat generation occurs from the combustion of gas or other fluid fuels, but particularly gas, by substituting for the program switch as shown in FIG. 10, as used to switch in and out circuits of heaters to raise or decrease the amount of heat being generated from electric heating elements, a turn valve operation as shown at the right side in FIG. 10, where the opening and closing of the turnvalve is accomplished as impelled by control motor 23, as it turns pinion gear 46 to turn in one direction and move ring gear 34 in a counterclockwise direction to open the valve and increase the volume of fuel gas being supplied to gas burners, and thus increase the amount of heat being generated therefrom, and as motor 23 turns or rotates in the other direction to move ring gear 34 in a clockwise direction and thus decrease or close the volume of fuel gas permitted to flow through to burning jets, and thus decrease the amount of heat being generated therefrom.

Valve action is impelled in a manner as follows: two fingers 47 protrude from ring gear 34 through holes in the valve wheel holes fit over said fingers 47 in a slideable manner and positioned to turn valve stem 48 in either direction on an axis which is common with that of ring gear 34, where valve stem 48 opens and closes fluid screw valve, thus increasing and decreasing and cutting off fuel flow, all from operations as described in the foregoing for operation of program switch shown also in FIG. 10. Provision must be made for metal housings enclosing burning jets to include also fuel and air (to support combustion) through pipes, and space sufficient for gas fired combustion to take place and thus transmit heat to metal surface of housing, and where housing is to be provided with sufficient exhaust ports and piping therefrom to conduct exhaust fumes out of, and away from the housing in which the combustion occurs. Provision must also be made for even heat generation from jets, one linear inch with another linear inch of the housing enclosing combustion and components in support thereof, and for heat generating jets to run the entire length of said metal housing containing combustion effects, where said housing must be inserted to run the entire length of heating jackets 7 .as shown in FIG. 7 or heating jacket 14 as shown in FIG. 11 and FIG. 12, and must provide for even passageway for air around between housing and inner surfaces of heating jacket. And provisions must be made, also for fuel feed to each of plural metal housings as inserted in plural, heating jackets operative in one heating level to by even, one housing with that of another, so that an even flow of uniformly heated air will obtain through each respective combustion housing involved in one level.

I claim:

1. In an enclosed electric heating oven, a metal outer surface overlaying an inner metal surface with a layer of flexible heat insulating material therebetween, an insulated door opening from one side thereof, a fan rotatably mounted from the top of said oven operable horizontally across the inner oven space, having partitions spaced apart along the right and left walls of the oven forming air passageways as separated from the cooking space for re-circulation of heated air, means carried by the oven casing for supporting object to be heated, clusters of plural electric heating coils and each said cluster being spaced apart from the other clusters, running from back to front horizontally disposed between the inner most partitions and below said objects to be heated, wing formed bafile jackets comprising heat insulating baflle plates partly surrounding said clusters of electric heating coils and preventing radiation from said heating coils, one wing of a baflle plate marginally overlapping the wing of an adjacent baffle plate providing air passageway therethrough, and having edges of bottom wings of adjacent baffle plates spaced apart to provide air passageway therethrough, electrical circuit means for supplying electric current to the heating coils operating singly, to generate heat according to pre-arranged switching controls, electrically responsive temperature sensing elements mounted between said heating coils and objects to be heated, said supporting means being adapted to permit currents of air to pass vertically therethrough as impelled by said fan in circulation through the oven and air passageways at the right and left, separator plate at top of the cooking space separating said oven surface edges thereof making a right angle junction with two innermost partitions, and running from back to front in the oven with a cut-out from the center to circumscribe the radius of the fan blade travel to separate the fan head from downward oven space and divert air from the oven to side passageways and vice versa, with horizontal separator plates making a right angle junction with the lower edges of the partitions to extend and bound air channels to individual heating jackets, an electric motor mounted and connected to drive said fan with variable speed switching means operable with temperature sensing response devices together :with a reversible motor wtih connecting electric current connections thereto through either one of two singly switched leads, one lead signifying the condition of under speed of the fan connected to rotate the motor in one direction, and the other lead signifying the condition of over speed for the fan connected to rotate the motor in the opposite direction with the motor drive connected to move the contact arm of the variable switch, another similar of overheating by electric heating coils connected to rotate the motor in the opposite direction having the motor drive connected to move the contact arm of the program switch at first switching means to pass current from the live bus bar feed, spacedly positioned buttons in an array of contact buttons along the laterally disposed program switch in separate lead circuits of control current to operate a second switching means of electromagnetic switches one said switch being operable for each circuit of heaters as actuated by the button contact with the movable arm of the program switch to energize any desired ones of the circuit of the electric heating coils to operate singly or simultaneously to vary heat generation up and down in desired manner.

2. An electric heating oven system according to claim 1, having electrical responsive temperature devices wherein a two-temperature point sensor control is extended to a common heat environment with pre-set temperature points set close but not quite together down as close as three degrees Fahrenheit apart with higher pre-set temperature singly switching currents, as fed in, to one of two conductor leads, signifying over-heat supply from the electric heating coils delivering heat therefrom, and a lower pre-set temperature point singly switching the same current, as fed in, to the other one of the two conductor leads signifying under heat supply from said heating coils, with sequential single switching means to prevent supply of current to both conductor leads simultaneously, and a reversible electric motor means to receive current from one of the two conductor leads as connected to a point in the mtor field coil, as one side of a power lead to the motor, to energize motor rota-tion in one direction, or to rent into directional rotatable energy with which to move alternately, as singly switched by temperature responsive devices, receive current from the other conductor lead as connected to another point in the field coils of said motor, as one side of a power feed to said motor to energize the motor to rotate in the opposite direction, thus converting, the temperature condition singly switched current into directional rotatable energy with which to move a movable contact arm of a variable switch as necessary for variable switch to respond to responsively vary the switching positions, which in turn, through its control current from a second circuit, feeds current as one side of another power feed, to the respective leads energizable coils of respective electromagnetic switches, each one of said electromagnetic switches being connected to close one side of a power feed to a respective circuit of said electric heating coils, any one of which circuits is operable in combinations with another of said circuits or other ones of said circuits to effect increases or decreases in output of heat generation in a continuous heat generating process, or for said driving motor to connectedly rotate the threaded shaft of the program switch, said combination utilizing two separate but identical transistorized Wheatstone bridge type make and break controllers, with a two degree differential, each controller having its individual thermistor sensing circuit, and also its individual temperature calibrated variable resistor, and each controller acting as a poney relay to operate a separate larger double pole electromagnetic switch, with each pole of said switch in reverse contact position with that of the other pole of said switch, namely one contactor pole closed circuit when said electromagnetic switch is deenergized, and open circuit when said switch is energized, with the other said pole of said switch in the opposite contact position, being open circuit when said switch is deenergized and closed circuit when said switch is energized, like poles of both said electromagnetic switches having stationary contacts connected together, with respective separate jumpers to sequential switching means whereby action of one said electromagnetic switch is dependent upon corresponding cooperative action of the other said electromagnetic switch which may occur at a differing temperature level, having movable contactors of both poles of one said electromagnetic switch connected in common to one in-coming lead of the power feed or power source, having the movable contactor on one pole of the other said electromagnetic switch being connected to one lead connected to the field coil of said motor at one point for motor rotation in one direction, and the movable contactor of the other said pole of said other electromagnetic switch being connected to an alternate lead connected to said field coil of said motor at another point, for motor rotation in the opposite direction, said motor having the ground lead being connected in the same power circuit, having thermistor sensing elements from both said controllers positioned in the same heat environment at a point of control common with both said sensing elements, the system being operable by utilization of the controller preset at the lower temperature level through action of the electromagnetic switch to which it is connected for energization of the switch coil to singly switch power to one power lead to one point of the motor coil as the controller makes or energizes, and continue to hold this in closed switch position until the temperature at ,the sensing point rises by two degrees Fahrenheit whereupon said controller deenergizes and thereby moves said signal switch position to open the circuit for said power lead to said one point of said motor coil, and by utilization of the other said controller preset at a higher temperature level through action of the other said electromagnetic switch to which it is connected for energization of the switch coil to break or deenergize and thereby singly close switch power to the other or alternate power lead connected at another point of said motor coil to continue to hold this signal switch position until the temperature level at the sensing point falls by two degrees Fahrenheit whereupon this controller becomes energized and thereby breaks the single switch position to open circuit, said motor being operable for either direction of rotation depending upon which of the two alternate power leads is supplying one side of circuit power feed to said motor, said method being equally operable through utilization of said devices including said motor in the same manner to remove by power drive a movable contact arm or wiper in either direction along a coil or grid resistor to lengthen or shorten resistence which may be connected in series with one side of the electric circuit to the fan motor and thus to vary the speed of the fan motor faster or slower as responsive to temperature levels in the heat environment in which both sensing elements are placed, said devices including said motor in the same manner to move by power drive a screw valve for infeed of fluid fuels, the screw valve operable in either direction, one direction to open the valve and increase fuel flow and thereby increase heat generation in combustion chamber where fuel is converted to heat, or in the other direction and thereby reduce the volume of heat generation, as responsive to temperature levels in said heat environment in which both thermistor sensor circuits are placed. 

